Telephone system.



E. .R. HOBBS.

TELEPHONE SYSTEM.

APPLICATION FILED MAY 15, 1909;

, wa'mmm m m mm m MWH v T D m m m l H2 ld m m m E. R.- HOBBS.

TELEPHONE SYSTEM.

APPLICATION FILED MAY15,1909.

1,045,845. Patented Dec.3,1912.

2 SHEETS SHEET 2.

TED STATES PATENT clinic.

ELBEB'I. 3.. mm, or BUHL, IDAHO.

TELEPHONE SYSTEM.

Patented Dec. 3, 1912.

Application aim Kay .15, 1969. Serial m. 496,127.

To all whom it may concern:

Be it known that I, Eumn'r R. Hones, a citizen of the United States, residin at iiuhl, in the county of Twin Falls and tate of Idaho, have invented certain new and useful Improvements in Telephone Svstems, of which the following is a speci cation, reference being had therein to the accompan ing drawing.

it y invention relates to telephone systems, and has for its object the provision of a novel means for etl'ecting connections at a central station betwen magneto and common batter line circuits.

provide the subscribers line terminal apparatus in a magneto circuit with means or affording an immediate bus test.

In a co-pending application .No. 464,860

filed November 28, 1908, I have shown-and described a device for putting the subscribers line terminals in a common battery system ,in'cQndition for an immediate busytcst and while I show and describe herein a test for a commonbattery circuit, this invention relates particularly to the. provision of means for accomplishing the same.

purpose in a ma neto circuit. To that end I have arrange an the answering and multiple jacks assooiatcd with the magneto line circuit, and have provided the dropsignal with-contact springs arranged to place said test sleeve in immediate condition for a busy test.

Other objects and advantages will appear in the detailed descri )tion of the system as hereinafter set fOl'tl l.

My invention is illustrated in the accoin-.

panying drawings in which:

Figure 1 shows a subscribers'ina eto line terminal ap aratus and multiple )tlCkS for use with tie operators cord-circuit shown in Fig. 2. Fig. 2 shows an operators cord-circuit. Fig. Bshcws a subscribers common battery line terminal a aratus. Fig. 4 is identical with Fig. 1. T ig. 5 is a modification of operators cord .cir cuit.. Fig. Guia a modifiedjform of subscribers tcrminala paratus. l I

In Fig. 1 the su scribersilineisi.v 1- and'2 .arc shown.leadingfrom the subscribers rabstation. ;(not.shown) both. of; said line s terminating in contacts ofJ the cut-oil relay iii. Connectcdwith.tlieset contacts isythe magneto: dro signalyD which may .be;of

any approve type,;either manuallyor mering. A further 0 ject of my invention is to an additional test sleeve the choking coils D an 'cciver chanically self-restorin The terminals of the lines are multiplied to the jacks J and J. Each jack consists of the sleeve rin r and the tip spring 8. Secured to the un er side of the tip spring is the insulating member 21 arranged to close the contacts 1; and 0' when the plug is inserted in the jack. A novel feature of this jack consists in an additional ring 6 which is provided for testing urposes only. This ring or sleeve is ma e considerably larger than the sleeve r so that when the plug is inserted it will not come in contact with the larger This additional sleeve may entirely or only partly encircle the line sleeve 1' or. to economize space it may be only an exposed iece of metal, as its use is merely for testmg. The test rings of the jacks are all connected to a common conductor connected with the spring a and with the spring d associated with the magneto drop D. The sprin d is extended and the end is dispose in such a osition that when the magneto D is energized the shutter will engage the end of thespring thereby breaking the contacts between the springs d and d and closing the contacts between cl and d.

The operators cord-circuit is provided with .the usual plugs P and P connected on the windings of the rain 5 R and R is connectedto the sleeve Sltt. of the cord, the

other end being normally rounded through respectively.

viators set consists of the usual The 0 I parts ant includes the transmitter T in cir- .Clllt with the battery B and the secondary windin a of an induction coil. The reis in circuit with the primary winding'cof the induction coil, together'with a condenser Q. ::A tertiary winding 1) is provided on theinduction coil for test purposes. one end of this coil is connected directly to ground and the other terminates in a contact of the calling supervisory relay R.

A listening key K is provided by means of which the operatorcan listen in to get the relay R controls the circuit of the/signal fee - the operatorsset as the lamp S keeps the tip side of the operators receiver at the potential of ground, so that-When the. tip of v plug P touches a jack Sleeve on which-the nected to ground through a circuit that includes a few windings of the supervisory .nect-s one terminal of its full winding to vground.

and the condenser Q, respectively,

their respective extensions 3 aud t leading 'to the jack 'J.

into the. condenser Q, giving the operator a lines or lines Whose resistance has been supervisory lamp would insure the positive tor after the, first operator has plugged in.

nnmbenwanted when a connection is desired; the operation of this key. serving to connect the test coil b with the tip side of the cord and the receiver A with the tip and sleei'e sides of the cord throughthe coil 0 g The ringing generator G is connected on one side to the ground and on the other to a contact arranged to be'closed by the ringing The apparatus shown in. Fig. 3 is'especially arranged to cotiperate with the cordcircuit in Fig. 2. I have shown therein the line wires 1 and 2 leading from a subscribers station (not shown) both of said lines.- terminating incontactsj of .the relay M, which-are of the make before break type, as willbe seen from thegdrawing. The-line Fig. 4 is identical with Fig. 1 and; its operation is therefore the same. In Fig. 5 there is no extratest winding to potential has been raised,- a charge [lows busy test. The supervisory lamp is con relay, this scheme admittin of the follow-' ing advantages: first it provides againstany possibility of the supervisory relay R op erating on the testcurrent of a second operutor, as this current divides at zv and. traverses the windin in opposite directions, the neutralizing e ect of the smaller winding being" suflicient to prevent the relay from operating; second, it insures. supervisionon long slightly raise'd as the current flowing from operation of supervisory relay; third, it cuts down the resistance between the lamp and sleeve side of cord c1rcuit,' thus providing a stronger busy test for a second opera- The' operation of the supervisory relay con- Fig.' 6 is somewhat similar tofXFig. 3.

However it makes use of a single winding on theline relay R instead of a doublewindmg,

, The operation ofj the system readily understoodfrom the .foregoing ex, planation of the apparatususedL air be Referring now to Fig.- 1,'whenja. subscriber desires a connection he operates his ringer,

current flowing overvline 2, through80, 9,

)10, 11, D, 12, 13, 14, 15, and back upon the line 1. Thereupon the armature 16 of the drop signal D is released and comes into engagement with the terminallTof thefspringcl breaking the contact/of the hitter with the spring 01 at 58 and closing thecontact .with the spring d at 59.- This serves to increase the potential of the niulti le jacks- J, J sincethev are now connected -through the conductor 20 and springs d and at to the battery B. The multiple jacks are thus 'n condition to test busy at once. On seeing the drop signal displayed the operator answers the call by placing the answering plug. P in the jack J If however before she has had time to insert the plug in its jack another subscriber should desireto com'muni cate with the calling subscriber, a secondoperator before whom the line of the second subscriber terminates, on testing the first snibscribers line in the ordinary way will find it busy even before the first operator has plugged in. The second operatorwill get a click in the ear due to a momentary current induced in the coil 0 caused by a flow of current from the ring of the calling subscribers multiple jack through the tip side of the cord plug (the cord of the second. operator), 24;, 25, 26, 27, 28, 29, b, 30 and ground[ A portion of the current from the ring of the multiple jack will flow. over the tip side 7 of the cord and to ground through the supervisory lamp '5'- and the choking coil D. This current, however, is small, due to the presence of 'the coil D, most of the current being forced throu h the test coil b It will be noted that t e drop D must be restored before the cut-oil relay can be energized. This restoring c'an'be accom- ;plishe'd in any ordinary-and desired manner, .7

either manually or automatically, means lfO for this purpose being common and well known. The simplest method however is for the operator to poke up' the drop with the tip of the plug just "as she inserts the latter into the jack. This would be the method followed. with simple apparatus'such as that shown in Fig. 1.

. \Vhen the first operator plugs into the answering jack the cut-off relay M is ener-, gized the energizing current being'from B,

21, c, c, 20, 58, 22, M, 23' to ground. The actuation of the cut-off relay M cuts out the drop signal I) through the breaking of the circuit at the contacts 91() and 1314. After plugging in toanswer the call the operator presses her listening key K and inquires the number wantedv Having learned the number she tests the wanted line by touching the tip of the calling plug P to the ring of the'jack. If the wanted subscriber' is busy the potential of his jack is raised in the manner described and current will flow through the test coil band a click will be heard; If the line is not busy the plug is inserted into the jack of the wanted subscriber. When the plug P is inserted in the jack the cut-ofirelay M of the called,

subscribers line is energized current flowing from battery, through the cut-off. relay, 3, tip side of jack, 7' tip ,side of plug, 24, 7, 19, S, 43, 51, D 52 and round. Thereupon the supervisory lamp S lights up. Ringing current is now supplied to the line on the manipulation of the ringing key Kr. Current then flows from the generator through 39, 40, p over the sleeve side of the subscribers line, through the subscribers ringer, back upon the tip side of the subscribers line, through 24, 41 and to ground. When the subscriber answers he closes the line circuit and provides another pathfor the current through his cut-off relay, this current flowing through the cut-off relay over theline wire 1. through the telephone. backupon the line Wire 2, through the sleeve side of thecord plug, conductor 40,

41, 8, 11 ,51, D and ground. Thereupon the supervisory relay R? is energized, the test circuit is broken at 42, the circuit of the supervisory lamp S is broken at 43 and a direct path to ground is provided by the closure ot'the contacts at 44. Battery current for the called subscriber is supplied through his cut-oft relay, through his in strument, back on the $lQ(\0 side 2 of the line and through the relay R Vith the arrangement described above the clearingout signal would .be operated by the called subscriber hanging up his receiver. When the operator withdraws the plugs from their jacks the system is r storedto its normal condition.

1 Having thus described my invention what I claim and desire to secure by Letters Pat ent is 1, In a telephone exchange system, subscribers lines comprising magneto circuits and common battery lines, an operators cord circuit, line controlled means for placing the line terminals or a calling subscriber 0n eitherthe magnetoor common battery lines in immediate condition for a busy test, means operable upon use of said cord circuit with any of the lines interchangeable for maintaining a busy test potential, said means acting automatically through the cord to disable the line controlled means of common battery lines and to maintain a busy test on said common battery lines and separate means adapted to be actuated by the operator for disabling the line controlled means of magneto lines.

2. In a telephone exchange system, subscribers lines'comprising magneto and common battery circuits, signals therefor, and means operated by the signal otthe magneto circuit for placin the terminals in immediate condition or a busy test.

3. In a telephone exchange system, a magneto line circuit, a drop signal therefor, answering and multiple jacks therefor and means actuated when the signal is displayed forplacing said answering and multiple jacks in immediate condition fora busy test.

4. In a telephone exchange system, a magneto line circuit provided with a drop sig nal, answering and multiple jacks provided with test contacts and means adapted to be engaged on the actuation of said drop signals to raise the. potential of said test contacts thereby providing for an immediate busy test.

5. In a telephone exchange system, a magneto line circuit provid'edwith a drop si -nal. answering and multiple jacks provide with sleeve and tip contacts, an additional test sleeve associated with each jack and means arranged to be actuated on the display of the drop signal for raising the potential of said test sleeve thereby providing for an immediate busy test! 6. In a telephone exchange system. a magneto line circuit. a drop signal associated therewith, answering and multiple jacks provided with sleeve and tip contacts. an additional test sleeve associated with each jack, contact springs adapted to be actuated on the display of said drop signal and arranged to raise the potential of said test sleeve thereby providing an immediate busy test.

In testimony whereof I aflix my signature in presence of two witnesses.

ELBERT R. HOBBS.

Witnesses:

JOHN W. Fame, WALTER BISHOP. 

